Micrometer.



Patented Aug. 5, |902. C. J. BANKS.

MICROM ETER.

(Application tiled July 5, 1899.)

(No Nadel.)

.E m W TTRNEYS UNITED STATES PATENT OEEICE.

CHARLES JOHN BANKS, OF WASHINGTON, ENGLAND.

IVIICROMETER.

SPECIFICATION forming* part of Letters Patent No. 706,148, dated August 5, 1902.

Application iiled July 5, 1899. Serial No. 722.856. (No model.)

To all whom, t nto/,y concer/'71,.-

Be it known that I, CHARLES JOHN BANKS, a subject of the Queen of Great Britain and Ireland, and a resident of Washington, in the county of Durham, England, have invented a certain new and useful Improved Micrometer, (for which I have applied for a patent in Great Britain under No. 26,426, dated December-l, 1898,) of which the following is a specification.

This invention relates Vto micrometers or instruments for gagng certain sizes of small objects or articles, such as the diameter of wire. f

` The micrometers generally used at present are of the screw type; but they possess disadvantages in the way of manipulation and reading which tend to inaccuracy, while their somewhat complex construction renders them costly to produce.

The object of my invention is to provide al micrometer or gage that can be cheaply manufactured, easily handled, and read directly or without recourse to mental calculation.

An instrument embodyinginy invention consists, essentially, of a tapered bar and a frame having a correspondingly-inclined surface for coacting therewith, the arrangement being such that between the bar and frame a space intervenes which is gradually increased or diminished on the movement of either, whereby any object placed therein is gaged and its measurement shown by a convenient scale or scales on one or both parts.

As will be obvious, my invention may be carried into practice by various constructions; but the construction that I prefer and find to attain my object very advantageously is shown in the accompanying drawings, in reference to which I will fully describe my invention.

In the drawings, Figure l is a side elevation of a complete micrometer, and Fig. 2 is a similar View with a part hereinafter described removed. Figs. 3 and 4 are end elevations at the left and right hand ends of Fig. 1, respectively; and Fig. `5 is a transverse section on the line Z Z in Fig. 2 looking to the left.

In the figures, A designates a bar or rule, and B an open-ended frame, box, casing, or

guide adapted to slide thereon or permit reciprocation of the bar A in or upon it. To permit these movements, the frame B is constituted by two plates b b, the former being plain, whereas the other is fashioned or recessed, as shown, to receive the bar A, which is retained in place by fixing both the plates together by screws b2 b2. The plate b is the part before alluded to as removed in Fig. 2. The upper edge of the bar A is tapered or inclined longitudinally and the lower edge made horizontal, whereat an appropriate scale a. is furnished. The upper and lower inner edges or surfaces of the frame B-Y-that is to say, of the recess in its plate-bare shaped to cor respond with the respective edges of the bar A, and they are at a distance apart equal to or about the saine as the greatest height or width of the bar or rule A. These features are clearly represented in Figs. l and 2.

At one end of the frame B and commencing at its lower inner edge a notch or gap b3 is made in the plates b Z9', forming `the sides or lateral walls thereof, while at the other end the lower portion of both these plates or walls is extended, and on that Vpart adjacent to the scale da Vernier-scale b4 is provided. For symmetry and greater accuracy I prefer to extend both the plates Z) b', as specified, though the plate b may only be so prolonged.

In Figs. 2 and 5 I show a plate b5 fitted in a recess in and screwed to the plate b', so as to form part of same about the lower margin of the notch b3. I recommend this plan, because the plate b5 can be easily adjustedto meet any adjustment that may be required in the instrument without necessitating the adj ustment of the essential components. Therefore convenience and economy accrue.

The bar A'is placed within the frameB with the inclined surfaces in contact, the maintenance of position being eected with the aid of a projection 196 (or there Imay be two or more) on thep'lateb taking into a groove a' in the bar A and by a spring 197 arranged t0 act on the under side of the bar A, the'spring being attached within the frame -plate b', suitably recessed therefor, by one of the screws b2 b2, as shown.

Obviously, the use of the parts b, a', and b? is not absolutely necessary, but I prefer IOO to employ them as they insure accuracy; of course, in place of them, other suitable or equivalent means may be adopted.

As Will now be apparent, the reading at the scales will be zero when the horizontal edge of the bar A is in contact with the corresponding edge of the frame B or the top of the plate b5, while as its recedes therefrom the reading graduallyincreases to the maximum. The scales a and b4 exemplified are based on the decimal system; but of course such will be determined by circumstances. However, whatever the scale the accuracy can always be proved by noting the length and travel of the bar or rule A and comparing the increase or decrease of the space at the notch b3 with the reading.

The parts herein described as comprisingr my improved micrometer may be constructed of any suitable material or materials known to those skilled in the art to which my invention belongs.

Having described the construction of my improved micrometer, I will now explain its operation in use. The vobject-say the wire C-to be gaged is inserted in the gap or notch b3. Then the bar A is moved toward same longitudinally through the frame B, whereby the spring b'f is depressed, and eventually the object C is nipped between the lower edge of the bar A and the adjacent edge of the frame B, owingto the diminution of the intervening space, as indicated by the dotted lines in Fig. 2, whereupon the requisite measurement is directly shown by and can be readily ascertained on referring to the scales a and b4. As will be evident, the same results will be attained by sliding the frame B (with the object C) backward on the bar A; but I find it more convenient to move the bar and maintain the frame more or less rigid. 7

What I claim as my invention, and desire to secure by Letters Patent, is

l. In combination, a graduated bar A llaving an inclined edge and provided with a groove a at one side parallel to the inclined edgeand a box B having a recess in which thetbar A can slide, one side of the recess being inclined similarly to the inclined edge of the bar, a projection bfor engaging the groove ct', and a spring 117 bearing on the bar, substantially as described.

2. ln combination, a graduated bar A having an inclined edge and provided withy a groove a' at one side parallel to the inclined edge, and a box B, having a recess in which the bar A can be slid, one side ot' the recess being inclined similarly to the inclined edge of the bar A, a projection b for engaging in the groove a', a notch or gap h3 at one end, an eX- tended graduated portion at the other end, and a spring 197, all arranged and adapted for operating substantially as described.

In witness whereof I have hereunto set my hand in the presence of two witnesses.

CHARLES JOHN BANKS.

Witnesses:

JAMES ANDREW HARVEY, ALFRED THOMAS BRATTON. 

